1. Field of the Invention
The present invention relates generally to an ice-making machine, and more particularly, to an ice-making machine reducing ice making time and reducing the amount of water to be frozen from being wasted.
2. Description of the Prior Art
An ice-making machine is used for freezing water to form pieces of ice. One proposal is for an ice-making machine capable of preventing opacification, which occurs as air bubbles inside the water are frozen. FIGS. 1 through 3 are views showing a conventional ice-making machine, such as that disclosed in the U.S. Pat. No.5,425,243.
As shown in FIGS. 1 through 3, a conventional ice-making machine includes a housing 10, a freezing unit 20, an air-removing means 30, and a detecting means 40 for detecting completion of the ice formation operation.
The housing 10 has an ice bin 11 for storing therein ice pieces formed in the freezing unit 20. Under the ice bin 11 are disposed a compressor 12 and a condenser 13, together comprising a freezing system.
As shown in FIG. 2, the freezing unit 20 includes a water tray 21, a freezing base plate 22 having a lower surface, and an evaporator 23. The water tray 21 is filled with the water to be frozen. A plurality of freezing fingers 24 are formed on the lower surface of the freezing base plate 22 to be dipped into the water in the water tray 21. At a side of the water tray 21 is provided a pivoting means 25 to discharge unfrozen water in the water tray 21 by tilting the water tray 21. The evaporator 23 is disposed on the upper surface of the freezing base plate 22 and is connected to a freezing system 12,13. As the refrigerant flows inside the evaporator 23, the freezing base plate 22 and the freezing fingers 24 are cooled utilizing heat exchange of the refrigerant.
The air-removing means 30 removes the air bubbles inside the water to be frozen, thereby preventing opacification from occurring during ice formation. The air-removing means 30 includes a rocking plate 31 vertically rocking inside the water tray 21 and a rocking motor 32 for driving the rocking plate 31. An engagement piece 33 disposed adjacent the rocking motor 32 pushes an engagement pin 34 upwardly of the rocking plate 31 to thereby move the rocking plate 31. Due to the rocking movement of the rocking plate 31, the air bubbles float upwardly and outside the water and thus are removed from the frozen ice pieces.
The detecting means 40 for detecting completion of the ice forming operation, as shown in FIG. 3, includes a forefinger switch 41, on which a lever 42 is disposed, and an actuation piece 44, disposed on a metal fitting 43 to which the rocking motor 32 is attached. When the rocking plate 31 collides with the ice pieces being gradually formed around the freezing fingers 24, the shock of the rocking plate 31 is transferred to the rocking motor 32 through the engagement piece 33. At this time, the metal fitting 43 is rotated on a supporting pivot shaft 45, so that the actuation piece 44, disposed at the metal fitting 43, presses the lever 42 to thus operate the forefinger switch 41.
The conventional ice-making machine further includes a water supply pipe 14, a pivotal shaft 26, a water chute 27, and a water collecting section 15, all of which are not further described herein as they are known in the conventional devices.
Hereinafter, the operation of the conventional ice-making machine is described.
When water to be frozen is supplied to the water tray 21 through the water supply pipe 14, to thus immerse the freezing fingers 24 dipped in the water, the water starts to be frozen around the freezing fingers 24 that are cooled at the temperature of 0xc2x0 C. or lower by the heat exchange of the refrigerant flowing inside the evaporator 23. At the same time, the rocking motor 32 is activated to vertically rock the rocking plate 31 immersed in the water. Accordingly, the water is vertically rocked and thus the air bubbles inside the water are removed by floating upwardly. As a result, clear ice pieces are formed around the freezing fingers 24.
The ice pieces are gradually formed around the freezing fingers 24 to have a predetermined size, and the rocking plate 31 collides with the ice pieces so that the shock of the rocking plate 31 is transferred to the rocking motor 32 via the engagement piece 33. At this time, the metal fitting 43 to which the rocking motor 32 is attached is rotated on the supporting shaft 45 in a clockwise direction so that the actuation piece 44 presses the lever 42 of the forefinger switch 41. Accordingly, the time of completion of the ice forming operation is detected. When the ice formation is completed, the rocking plate 31 stops being rocked, hot gas is discharged from the compressor 12 and is supplied directly to the evaporator 23 without passing through the condenser 13 to temporarily heat the freezing fingers 24, and the water tray 21 pivots on the pivotal shaft 26 by the pivoting means 25 to thus be tilted. Accordingly, the formed ice pieces are separated from the freezing fingers 24 and are dropped into the ice bin 11. The unfrozen water that remains in the water tray 21 is guided by the water chute 27 and is discharged to the water collecting section 15.
Such conventional ice-making machines require an amount of water exceeding what is actually to be frozen as the water tray is designed to hold more than the amount of water necessary to make ice pieces, thereby wasting a lot of water.
Moreover, since the freezing fingers 24 cool not only the water around the freezing fingers 24 but also cool all of the water in the water tray 21, excessive energy is consumed and the growth rate of the ice pieces formed around the freezing fingers 24 is unnecessarily reduced.
The present invention has been developed in order to solve the above problems of the prior, art conventional ice-making machines. Accordingly, an object of the present invention is to provide an ice-making machine reducing the amount of water to be frozen that is cooled by supplying a predetermined amount of water into a plurality of freezing chambers having a predetermined size, and shortening the time required to form ice pieces by increasing the freezing rate.
The above object is achieved by providing an ice-making machine comprising a housing, an evaporator connected to a freezing system, a base frame having a plurality of freezing cells for receiving water to be frozen, a freezing base plate on which the evaporator is disposed, the freezing base plate having a lower surface and freezing fingers formed thereon to be dipped into the water supplied to the freezing cells, and an air-removing means for rocking the base frame to remove air bubbles from the water to be frozen.
Preferably, the air-removing means comprises a supporting frame for movably supporting the base frame and enabling it to rock upward and downward, a spring interposed between the base frame and the supporting frame, and a pressing means for repeatedly pressing the base frame, and the base frame being capable of rocking upward and downward due to the elastic recovering force of the spring and the pressure of the pressing means so that the water in the freezing cells are applied to the freezing fingers repeatedly.
Also, it is preferred that the pressing means comprises a cam disposed for contact with the base frame and a cam motor for rotating the cam.
Also, it is preferred that the base frame has a sliding bar for being inserted into a sliding hole formed in the supporting frame.
Also, the ice making machine further comprises a detecting means for detecting completion of the ice forming operation by detecting a variation in the distance within which the base frame is being rocked, the variation depending on the sizes of the ice pieces formed around the freezing fingers.
Preferably, the detecting means comprises a magnetic sensor for sensing a variation in the magnetic force caused by the rocking base frame to detect when the ice pieces formed around the freezing fingers reach the predetermined sizes.
Preferably, a blocking segment moving vertically between both sensing portions of the magnetic sensor is movably provided at a side of the supporting frame, and the magnetic sensor is disposed at the base frame for detecting the variation in the magnetic force caused by the movement of the blocking segment when the base frame is rocked upward and downward.